function adj_mat = default_dat()
adj_mat = [0 99 66 inf 13 15 25;
           99 0 13 12 6 8 8;
           66 13 0 2 3 6 4;
           inf 12 2 0 3 77 54;
           13 6 3 3 0 23 12;
           15 8 6 77 23 0 56; 
           25 8 4 54 12 56 0];